The jury decided yesterday he did make something of himself — a criminal.

A little more than two years after she died at 105, the panel agreed that he helped himself to more than $60 million of his socialite mother’s fortune, forever tarnishing the name of one of New York’s most distinguished families.

Thanks to his family connections, Marshall, 85, has had a variety of careers — including theatrical producer, Marine, CIA intelligence officer and ambassador.

His mom once quipped, “It cost more than $100,000″ for his ambassadorships, referring to political contributions that greased the way for the appointments.

Now his title is convicted felon, and he faces the prospect of spending up to 25 years — almost certainly the rest of his life — behind bars.

Marshall, known as Tony, was born May 30, 1924. His dad was Brooke Astor’s first husband, New Jersey state Sen. John Dryden Kuser.

Marshall’s relations with his father were somewhat strained. But he adored his mother’s second husband, stockbroker and socialite Charles Marshall, and adopted his surname when he turned 18.

Charles Marshall was the love of Brooke Astor’s life, but he died early, forcing her to turn to magazine writing to maintain her lifestyle. She soon accepted a proposal from millionaire Vincent Astor, of the renowned real-estate and fur-trading clan.

Her disappointing son always seemed to be an afterthought. She would go off on trips for months at a time, leaving him at her Park Avenue penthouse.

Tony attended the Brooks School in North Andover, Mass. He enlisted in the Marine Corps in 1942 and became a war hero, winning the Purple Heart for leading a contingent of soldiers into battle at Iwo Jima. After the war, he enrolled in Brown University.

From 1958 to 1959, Marshall was the US consul in Istanbul, and from 1969 to 1971, he was the US ambassador to the Malagasy Republic (now Madagascar). From 1972 to 1974, he was ambassador to Trinidad and Tobago.

In the 1980s, he was an officer with the United States Trust Company of New York, working on large estate accounts.

Marshall married his first wife, Elizabeth Cryan, in Wynnewood, Pa., in July 1947. They had twin sons, Alexander, now a photographer, and Philip, currently a professor of architectural preservation at Roger Williams University in Bristol, RI.

Philip would prove to be his father’s undoing.

Marshall married his second wife, Thelma Hoegnell, in December 1962. They divorced 28 years later, after he had a fling with Charlene Gilbert, the wife of an Episcopal priest in Northeast Harbor, Maine.

Northeast Harbor is a blueblood enclave on Mount Desert Island, where Bar Harbor is located. Marshall met Charlene while summering there — his mother had a mansion in the tony town. He and Charlene were married in 1992.

Tony and Charlene, who was born poor, lived the good life. They became Broadway producers, doing such shows as “Long Day’s Journey into Night” (2003) and “I Am My Own Wife” (2004), which won a Tony.

Brooke had spent a lifetime underwriting Tony’s lifestyle — buying him a $2.9 million apartment and paying him $450,000 a year to manage her money.

Tony had the legal authority to act on her behalf in some financial matters.

Brooke instructed Tony that she wanted her grandson Philip to inherit her Northeast Harbor home.

But Tony disobeyed her, took over the ownership himself and transferred it to Charlene, whom Brooke detested.

Marshall was eventually forced to give it back to his mother.

In 2006, Philip filed a suit accusing his father of neglecting the care of his Alzheimer’s-inflicted grandmother by refusing to fill her prescriptions, keeping her apart from her beloved dogs, Boysie and Girlsie, and forcing her to sleep on a couch that reeked of urine.

The civil suit was settled but led to criminal charges being filed against Marshall.

Among other things, he was accused of talking his mother into believing she couldn’t buy another dress until she sold her favorite painting — impressionist Childe Hassam’s masterpiece “Up the Avenue from Thirty-Fourth Street, May 1917″– for $10 million. Marshall allegedly pocketed $2 million of the price of the sale.

Astor seemed to have her son figured out.

“You only want to come to see how soon I’m going to die,” she told him at one point.

The trial began at the end of March. Marshall soon suffered a stroke that sidelined him for two days. In July, he became dizzy and fell in the bathroom during a break. He was taken to the hospital on a stretcher.

But, through it all, he kept his emotions in check, mostly staring straight ahead. He maintained that pose when he was convicted yesterday.